Question Postfix SMTP: timed out while receiving the initial server greeting

[Kristo]

Some of my mail users are reporting that their mails are sometimes spinning and waiting for around 5 minutes before they "go out" from their mail client.

Here is a log entry which has quite long delay time (mostly because of the target relay)

postfix/smtp ... relay=mxlb.ispgateway.de[...]:25, delay=304, delays=3.6/0.01/300/0, dsn=4.4.2, status=deferred (conversation with mxlb.ispgateway.de[...] timed out while receiving the initial server greeting)

But this process shouldn´t be responsible for the mail clients. Isn´t that already happening on the server while the mails are in queue?

How do I track down such a report: "My mail took so long before it is sent"?

 

[WebHostingAce]

Have you tried yourself to recreate this issue?

"My mail took so long before it is sent" - this may depend on any attachment size or client internet speed.. etc